<?php

namespace GetId3\Module\Audio;

use GetId3\Handler\BaseHandler;
use GetId3\Lib\Helper;

/////////////////////////////////////////////////////////////////
/// GetId3() by James Heinrich <info@getid3.org>               //
//  available at http://getid3.sourceforge.net                 //
//            or http://www.getid3.org                         //
/////////////////////////////////////////////////////////////////
// See readme.txt for more details                             //
/////////////////////////////////////////////////////////////////
//                                                             //
// module.audio.monkey.php                                     //
// module for analyzing Monkey's Audio files                   //
// dependencies: NONE                                          //
//                                                            ///
/////////////////////////////////////////////////////////////////

/**
 * module for analyzing Monkey's Audio files
 *
 * @author James Heinrich <info@getid3.org>
 *
 * @link http://getid3.sourceforge.net
 * @link http://www.getid3.org
 */
class Monkey extends BaseHandler
{
    /**
     * @return bool
     */
    public function analyze()
    {
        $info = &$this->getid3->info;

        // based loosely on code from TMonkey by Jurgen Faul <jfaulØgmx*de>
        // http://jfaul.de/atl  or  http://j-faul.virtualave.net/atl/atl.html

        $info['fileformat'] = 'mac';
        $info['audio']['dataformat'] = 'mac';
        $info['audio']['bitrate_mode'] = 'vbr';
        $info['audio']['lossless'] = true;

        $info['monkeys_audio']['raw'] = array();
        $thisfile_monkeysaudio = &$info['monkeys_audio'];
        $thisfile_monkeysaudio_raw = &$thisfile_monkeysaudio['raw'];

        fseek($this->getid3->fp, $info['avdataoffset'], SEEK_SET);
        $MACheaderData = fread($this->getid3->fp, 74);

        $thisfile_monkeysaudio_raw['magic'] = substr($MACheaderData, 0, 4);
        $magic = 'MAC ';
        if ($thisfile_monkeysaudio_raw['magic'] != $magic) {
            $info['error'][] = 'Expecting "'.Helper::PrintHexBytes($magic).'" at offset '.$info['avdataoffset'].', found "'.Helper::PrintHexBytes($thisfile_monkeysaudio_raw['magic']).'"';
            unset($info['fileformat']);

            return false;
        }
        $thisfile_monkeysaudio_raw['nVersion'] = Helper::LittleEndian2Int(substr($MACheaderData, 4, 2)); // appears to be uint32 in 3.98+

        if ($thisfile_monkeysaudio_raw['nVersion'] < 3980) {
            $thisfile_monkeysaudio_raw['nCompressionLevel'] = Helper::LittleEndian2Int(substr($MACheaderData, 6, 2));
            $thisfile_monkeysaudio_raw['nFormatFlags'] = Helper::LittleEndian2Int(substr($MACheaderData, 8, 2));
            $thisfile_monkeysaudio_raw['nChannels'] = Helper::LittleEndian2Int(substr($MACheaderData, 10, 2));
            $thisfile_monkeysaudio_raw['nSampleRate'] = Helper::LittleEndian2Int(substr($MACheaderData, 12, 4));
            $thisfile_monkeysaudio_raw['nHeaderDataBytes'] = Helper::LittleEndian2Int(substr($MACheaderData, 16, 4));
            $thisfile_monkeysaudio_raw['nWAVTerminatingBytes'] = Helper::LittleEndian2Int(substr($MACheaderData, 20, 4));
            $thisfile_monkeysaudio_raw['nTotalFrames'] = Helper::LittleEndian2Int(substr($MACheaderData, 24, 4));
            $thisfile_monkeysaudio_raw['nFinalFrameSamples'] = Helper::LittleEndian2Int(substr($MACheaderData, 28, 4));
            $thisfile_monkeysaudio_raw['nPeakLevel'] = Helper::LittleEndian2Int(substr($MACheaderData, 32, 4));
            $thisfile_monkeysaudio_raw['nSeekElements'] = Helper::LittleEndian2Int(substr($MACheaderData, 38, 2));
            $offset = 8;
        } else {
            $offset = 8;
            // APE_DESCRIPTOR
            $thisfile_monkeysaudio_raw['nDescriptorBytes'] = Helper::LittleEndian2Int(substr($MACheaderData, $offset, 4));
            $offset += 4;
            $thisfile_monkeysaudio_raw['nHeaderBytes'] = Helper::LittleEndian2Int(substr($MACheaderData, $offset, 4));
            $offset += 4;
            $thisfile_monkeysaudio_raw['nSeekTableBytes'] = Helper::LittleEndian2Int(substr($MACheaderData, $offset, 4));
            $offset += 4;
            $thisfile_monkeysaudio_raw['nHeaderDataBytes'] = Helper::LittleEndian2Int(substr($MACheaderData, $offset, 4));
            $offset += 4;
            $thisfile_monkeysaudio_raw['nAPEFrameDataBytes'] = Helper::LittleEndian2Int(substr($MACheaderData, $offset, 4));
            $offset += 4;
            $thisfile_monkeysaudio_raw['nAPEFrameDataBytesHigh'] = Helper::LittleEndian2Int(substr($MACheaderData, $offset, 4));
            $offset += 4;
            $thisfile_monkeysaudio_raw['nTerminatingDataBytes'] = Helper::LittleEndian2Int(substr($MACheaderData, $offset, 4));
            $offset += 4;
            $thisfile_monkeysaudio_raw['cFileMD5'] = substr($MACheaderData, $offset, 16);
            $offset += 16;

            // APE_HEADER
            $thisfile_monkeysaudio_raw['nCompressionLevel'] = Helper::LittleEndian2Int(substr($MACheaderData, $offset, 2));
            $offset += 2;
            $thisfile_monkeysaudio_raw['nFormatFlags'] = Helper::LittleEndian2Int(substr($MACheaderData, $offset, 2));
            $offset += 2;
            $thisfile_monkeysaudio_raw['nBlocksPerFrame'] = Helper::LittleEndian2Int(substr($MACheaderData, $offset, 4));
            $offset += 4;
            $thisfile_monkeysaudio_raw['nFinalFrameBlocks'] = Helper::LittleEndian2Int(substr($MACheaderData, $offset, 4));
            $offset += 4;
            $thisfile_monkeysaudio_raw['nTotalFrames'] = Helper::LittleEndian2Int(substr($MACheaderData, $offset, 4));
            $offset += 4;
            $thisfile_monkeysaudio_raw['nBitsPerSample'] = Helper::LittleEndian2Int(substr($MACheaderData, $offset, 2));
            $offset += 2;
            $thisfile_monkeysaudio_raw['nChannels'] = Helper::LittleEndian2Int(substr($MACheaderData, $offset, 2));
            $offset += 2;
            $thisfile_monkeysaudio_raw['nSampleRate'] = Helper::LittleEndian2Int(substr($MACheaderData, $offset, 4));
            $offset += 4;
        }

        $thisfile_monkeysaudio['flags']['8-bit'] = (bool) ($thisfile_monkeysaudio_raw['nFormatFlags'] & 0x0001);
        $thisfile_monkeysaudio['flags']['crc-32'] = (bool) ($thisfile_monkeysaudio_raw['nFormatFlags'] & 0x0002);
        $thisfile_monkeysaudio['flags']['peak_level'] = (bool) ($thisfile_monkeysaudio_raw['nFormatFlags'] & 0x0004);
        $thisfile_monkeysaudio['flags']['24-bit'] = (bool) ($thisfile_monkeysaudio_raw['nFormatFlags'] & 0x0008);
        $thisfile_monkeysaudio['flags']['seek_elements'] = (bool) ($thisfile_monkeysaudio_raw['nFormatFlags'] & 0x0010);
        $thisfile_monkeysaudio['flags']['no_wav_header'] = (bool) ($thisfile_monkeysaudio_raw['nFormatFlags'] & 0x0020);
        $thisfile_monkeysaudio['version'] = $thisfile_monkeysaudio_raw['nVersion'] / 1000;
        $thisfile_monkeysaudio['compression'] = $this->MonkeyCompressionLevelNameLookup($thisfile_monkeysaudio_raw['nCompressionLevel']);
        if ($thisfile_monkeysaudio_raw['nVersion'] < 3980) {
            $thisfile_monkeysaudio['samples_per_frame'] = $this->MonkeySamplesPerFrame($thisfile_monkeysaudio_raw['nVersion'], $thisfile_monkeysaudio_raw['nCompressionLevel']);
        }
        $thisfile_monkeysaudio['bits_per_sample'] = ($thisfile_monkeysaudio['flags']['24-bit'] ? 24 : ($thisfile_monkeysaudio['flags']['8-bit'] ? 8 : 16));
        $thisfile_monkeysaudio['channels'] = $thisfile_monkeysaudio_raw['nChannels'];
        $info['audio']['channels'] = $thisfile_monkeysaudio['channels'];
        $thisfile_monkeysaudio['sample_rate'] = $thisfile_monkeysaudio_raw['nSampleRate'];
        if ($thisfile_monkeysaudio['sample_rate'] == 0) {
            $info['error'][] = 'Corrupt MAC file: frequency == zero';

            return false;
        }
        $info['audio']['sample_rate'] = $thisfile_monkeysaudio['sample_rate'];
        if ($thisfile_monkeysaudio['flags']['peak_level']) {
            $thisfile_monkeysaudio['peak_level'] = $thisfile_monkeysaudio_raw['nPeakLevel'];
            $thisfile_monkeysaudio['peak_ratio'] = $thisfile_monkeysaudio['peak_level'] / pow(2, $thisfile_monkeysaudio['bits_per_sample'] - 1);
        }
        if ($thisfile_monkeysaudio_raw['nVersion'] >= 3980) {
            $thisfile_monkeysaudio['samples'] = (($thisfile_monkeysaudio_raw['nTotalFrames'] - 1) * $thisfile_monkeysaudio_raw['nBlocksPerFrame']) + $thisfile_monkeysaudio_raw['nFinalFrameBlocks'];
        } else {
            $thisfile_monkeysaudio['samples'] = (($thisfile_monkeysaudio_raw['nTotalFrames'] - 1) * $thisfile_monkeysaudio['samples_per_frame']) + $thisfile_monkeysaudio_raw['nFinalFrameSamples'];
        }
        $thisfile_monkeysaudio['playtime'] = $thisfile_monkeysaudio['samples'] / $thisfile_monkeysaudio['sample_rate'];
        if ($thisfile_monkeysaudio['playtime'] == 0) {
            $info['error'][] = 'Corrupt MAC file: playtime == zero';

            return false;
        }
        $info['playtime_seconds'] = $thisfile_monkeysaudio['playtime'];
        $thisfile_monkeysaudio['compressed_size'] = $info['avdataend'] - $info['avdataoffset'];
        $thisfile_monkeysaudio['uncompressed_size'] = $thisfile_monkeysaudio['samples'] * $thisfile_monkeysaudio['channels'] * ($thisfile_monkeysaudio['bits_per_sample'] / 8);
        if ($thisfile_monkeysaudio['uncompressed_size'] == 0) {
            $info['error'][] = 'Corrupt MAC file: uncompressed_size == zero';

            return false;
        }
        $thisfile_monkeysaudio['compression_ratio'] = $thisfile_monkeysaudio['compressed_size'] / ($thisfile_monkeysaudio['uncompressed_size'] + $thisfile_monkeysaudio_raw['nHeaderDataBytes']);
        $thisfile_monkeysaudio['bitrate'] = (($thisfile_monkeysaudio['samples'] * $thisfile_monkeysaudio['channels'] * $thisfile_monkeysaudio['bits_per_sample']) / $thisfile_monkeysaudio['playtime']) * $thisfile_monkeysaudio['compression_ratio'];
        $info['audio']['bitrate'] = $thisfile_monkeysaudio['bitrate'];

        // add size of MAC header to avdataoffset
        if ($thisfile_monkeysaudio_raw['nVersion'] >= 3980) {
            $info['avdataoffset'] += $thisfile_monkeysaudio_raw['nDescriptorBytes'];
            $info['avdataoffset'] += $thisfile_monkeysaudio_raw['nHeaderBytes'];
            $info['avdataoffset'] += $thisfile_monkeysaudio_raw['nSeekTableBytes'];
            $info['avdataoffset'] += $thisfile_monkeysaudio_raw['nHeaderDataBytes'];

            $info['avdataend'] -= $thisfile_monkeysaudio_raw['nTerminatingDataBytes'];
        } else {
            $info['avdataoffset'] += $offset;
        }

        if ($thisfile_monkeysaudio_raw['nVersion'] >= 3980) {
            if ($thisfile_monkeysaudio_raw['cFileMD5'] === str_repeat("\x00", 16)) {
                //$info['warning'][] = 'cFileMD5 is null';
            } else {
                $info['md5_data_source'] = '';
                $md5 = $thisfile_monkeysaudio_raw['cFileMD5'];
                for ($i = 0; $i < strlen($md5); ++$i) {
                    $info['md5_data_source'] .= str_pad(dechex(ord($md5{$i})), 2, '00', STR_PAD_LEFT);
                }
                if (!preg_match('/^[0-9a-f]{32}$/', $info['md5_data_source'])) {
                    unset($info['md5_data_source']);
                }
            }
        }

        $info['audio']['bits_per_sample'] = $thisfile_monkeysaudio['bits_per_sample'];
        $info['audio']['encoder'] = 'MAC v'.number_format($thisfile_monkeysaudio['version'], 2);
        $info['audio']['encoder_options'] = ucfirst($thisfile_monkeysaudio['compression']).' compression';

        return true;
    }

    /**
     * @staticvar array $MonkeyCompressionLevelNameLookup
     *
     * @param  type $compressionlevel
     *
     * @return type
     */
    public function MonkeyCompressionLevelNameLookup($compressionlevel)
    {
        static $MonkeyCompressionLevelNameLookup = array(
            0 => 'unknown',
            1000 => 'fast',
            2000 => 'normal',
            3000 => 'high',
            4000 => 'extra-high',
            5000 => 'insane',
        );

        return (isset($MonkeyCompressionLevelNameLookup[$compressionlevel]) ? $MonkeyCompressionLevelNameLookup[$compressionlevel] : 'invalid');
    }

    /**
     * @param  type $versionid
     * @param  type $compressionlevel
     *
     * @return int
     */
    public function MonkeySamplesPerFrame($versionid, $compressionlevel)
    {
        if ($versionid >= 3950) {
            return 73728 * 4;
        } elseif ($versionid >= 3900) {
            return 73728;
        } elseif (($versionid >= 3800) && ($compressionlevel == 4000)) {
            return 73728;
        } else {
            return 9216;
        }
    }
}
